To change Date format in a disorderly column

[pmich]

Sub M_snb()
    [K2:K200] = [if(B2:B200="","",if(isnumber(B2:B200),B2:B200,date(right(trim(B2:B200),4),substitute(mid(B2:B200,search("/",B2:B200)+1,2),"/",""),substitute(left(substitute(B2:B200,"`",""),2),"/",""))))]
End Sub

Thanks for the quick reply.
It changes dates into numbers. Afterwards I formatted the cells manually as DD/MM/YYYY.
After 31/1/2011, the date 02/01/2011 remains as it is. It should be changed as 01/02/2011.
Similarly, after 09/02/2011, the date 02/10/2011 remains as it is. It should be changed as 10/02/2011.